1. Field of the Invention
The present invention relates to an inference planning system which is for making production plans, facility layouts and so on in manufacturing.
2. Description of the Related Art
Recently, with technological innovations or changes of consumer preference, rapid design changes in manufacturing have become common. That is, recently, many types of goods need to be manufactured, with relatively small quantities for each of the many types, within a short time period before an appointed date of delivery thereof. The above-mentioned manufacturing with many changes after relatively short periods of time becomes very important to keep up with quickly changing market trends. Therefore, it is desired that rapid and accurate production plans and facility layouts are made. Furthermore, quick responses to frequent changes of the plans and consecutive modifications for filling in gaps between planning and results of production are needed.
For instance, Japanese unexamined published patent application (Tokkai sho 62-52666) discloses a prior art of a planning system. An outline of the prior art will be described with reference to FIG. 33, which shows a schematic block diagram of the conventional planning system for production. Numeral 101 designates a storage device for storing basic data, e.g. types of manufacturing devices, their facilities, quantities, capacity and layout thereof. Numeral 102 designates an input device for inputting data of types of products to be produced and quantity (numbers) thereof, namely data of products. Numeral 108 designates a central processing unit (CPU) having a program 103 for production planning which makes a production plan. The program 103 uses a storage device 104 as a memory for storing many variables used in making the plan based on the above-mentioned basic data and data of products. Numeral 105 designates a display for indicating a production plan which has been made by this system. Numeral 106 is a printer for printing out the production plan. Numeral 107 designates a storage device for storing the production plan.
The CPU (central processing unit) controls the above-mentioned devices, equipments and program. In the abovementioned system, the method for making the production plan comprises the steps of: (1) inputting the above-mentioned data of products by the input device 102; (2) making or developing a production plan automatically by utilizing the program 103 for production planning and then storing the developed production plan in the storage device 104, whereby the production plan development is accomplished by combining the basic data stored in the storage device 101 with the data for products in the (CPU); (3) storing the production plan in the storage device 107; (4) displaying the production plan with the display 105; and (5) printing the production plan with the printer 106.
However, in the case that the production plan is not satisfactory or some modification of the plan is necessary due to newly requested changes in product or system specifications, the structure of the above-mentioned device needs to produce an entirely new plan for production planning from the beginning. Such modification requires additional time for processing, and results in a problem of low efficiency in planning. Therefore, because of the above-mentioned low efficiency in modification, a first problem is that the conventional method cannot update frequent modifications in planning by filling up a gap between the plan and the real data which is being sampled at every moment.
Japanese unexamined published patent application (Tokkai sho 63-291166) discloses another conventional planning system. This conventional planning system develops the production plan more easily because a planner uses an interactive method for making the operation plan of the facilities of interest. In this system, operation conditions of facilities are input by a keyboard, and the data representing these conditions are displayed on a CRT display as a table of a plan. The planner can produce the operation plan interactively by scrolling the table of the plan on the CRT display and by using a pointing device for pointing out a position on the CRT display to insert or shift select a menu list of predetermined operations.
In the above-mentioned system, although it is easy to correct the plan, all correction for change of data needs to be input interactively, and the planner must check and correct each point of planning so that the corrections will make the appropriate connections to other points of the plan. The prior art hence has the problem of inefficiency in correction and low reliability of planning.
Furthermore, there are limitations of changeable data and changeable methods in the prior art. The above-mentioned related art has no capability to change, for example, some kinds of data, methods of planning, formatting of output and so on.
Still further, the prior art has the problem of limitations in the usable area for planning.